I use Crostini now but used Crouton a lot before Crostini was available. Without Crouton I never had that problem, but I did occasionally have to rebuild because my kids would reboot it and press the spacebar like the scary boot message told them too :facepalm:

With Crostini something did happen that horked the VM and I had to remove and reinstall it. That is pretty annoying. Not sure if I did something to cause it, but I also respect that the feature is still "Beta" and I guess I'm so overjoyed that they're doing it that I'm willing to accept some brokenness :-)